Question

Part 3: Crossing Tail-Feather Length and Feather Color

Cross a P generation, LlBb with llbb. Assume the following F1 generation:
LlBb: 480
Llbb: 20
llBb: 20
llbb: 480
(Score for Question 1: ___ of 2 points)
1. Which offspring are not the recombinant offspring in this cross?
Answer:
Type your answer here.
(Score for Question 2: ___ of 2 points)
2. How far apart are L and B?
Answer:
Type your answer here.

Answer 1

Q: 1. Which offspring are not the recombinant offspring in this cross?

It is mentioned in the question that we are crossing Tail-Feather Length and Feather Color with short feather length and recessive feather color organisms.

P1: LlBb X llbb

Gametes: LB: Lb: lB: lb : lb

Offspring:

• LlBb: 480
• Llbb: 20
• llBb: 20
• llbb: 480

So as we see that perntal combinations are LlBb and llbb which means 480 + 480 organisms are just like parents while Llbb: 20 and llBb: 20 (20 +20=40) are recombinants.

Answer: It means that number of recombinants are 40.

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Q2: How far apart are L and B?

To answer this question we will use a formula:

The distance between L and B = Total number of recombinant types/ total number of offspring X 100

It means that distance between L and B= 40/1000 X 100

= 4

Answer: It means L and B are 4 units apart because they make up 4 % of the total recombinant types. you just saw how we did it.

Hope it help! :)